It has long been an open secret among heart doctors: Flaws in the fragile wires, or "leads," connecting cardiac electrical devices to patients' hearts are far more frequent than malfunctions in the devices themselves.

Now that Medtronic Inc. has pulled its Sprint Fidelis leads from the market due to their risk of fracturing, hundreds of thousands of heart patients have been alerted to that reality. And they must decide how to respond.

The company, which says that 235,000 patients world-wide have a Sprint Fidelis attached to their hearts, recommends that patients see their doctors immediately. A cardiologist can reprogram a patient's defibrillator to heighten its ability to sense a defect in a lead so it can send out a warning beep if a problem is detected. Some doctors are also recommending that patients sign up for Medtronic's monitoring system, known as CareLink, which could alert patients to a possible fracture in the lead.